The problem (for now) ended up being a bad valve body in the re manufactured transmission that they installed. There was no charge to fix it, but they had it another week and I had spent over $700 to have the motor mounts replaced when that wasn't the problem.

I updated my original post on May 08, 2013 #481. We've never had the car serviced, nor has the problem reoccurred. I manage my fluids myself, changed the oil last weekend. The tranny fluid looked in good shape, up to the top of the level. My wife wants to not press the issue, and get rid of the car altogether, before it starts trouble again, and breaks the bank.

Amen brother! Of all the bs talk from customer service as to what could be wrong with my 06 GXP Tranny, you sir sound like you have the ultimate answer.I just turned 80k on mine and Its time for an import! No more Garbage Motors!Thanks for the 411.

I have been reading the Pontiac Grand Prix GXP transmission posts with interest and decided to post hoping someone from Gm would see this and respond, or maybe someone could tell me how to reach some one in authority at GM. I just had my fourth,that's right fourth transmission installed in my GXP in 89,000 miles.The dealer who rebuilt the other transmissions "only" charged me $1621.00 this time it was out of warranty by about 18 days and could not be covered under the 100000 mile ,3 year guarantee. Last time it was $1850 or so. The time before it was only $ 500.00 that one lasted approximately 2,000 miles. When i picked up the car it had many new scratches and a nice new ding. The heads up display also did not work. Back to the dealer today they tell me the problem is inside the dashboard and not related. WhenI called GM I had the pleasure of speaking to someone named Tommy who sounded like he was stoned. He could not string together a even half coherent sentence had no answers just told me my car was out of warranty. Anybody have any Ideas, could really use some help.

i have found the website i was talking about. they say they have fixed the flaws in the pontiac trannys. im fixin to get one for mine. try www.tripleedgeperformance.com the high performance one is right under $1900.00 and you can also add other stuff to make it better. they build it when you order it. i hope this helps. misty

I would like to thank all the people who responded to my earlier post. I heard from pontiac the very next morning, they were very concerned about my situation. After three weeks of being shuffled from one person to the next, I was told there was nothing they could do for me because my vehicle was out of warranty. They stated that they had helped me through their assistance program by reducing the price of the transmissions. I responded by asking them if they considered transmissions a wear item and asking them to give me an answer as to why I would need four transmissions in 89,000 miles. They only would repeat their mantra that they had helped me and my vehicle was out of warranty. This has been a very frustrating and eye opening experience. Not sure what my next move will be considering a lawsuit have spoken to my attorney.

Hi,
my automatic transmission is not working. I now have to put the car in manual gear and use the tap shift to drive. the car hesitates a lot in first gear, and the transmission seems to be sliping in manual gear. I don't understand why the automatic transmission does not work??
2005 I'm at Grand Prix GXP
98,000 mi

Hello everyone...I'm the owner of a 07 grand prix.. I've had my car for about 2 years now..one month into owning it, fuel pump went. The car was still under warranty so it didn't kill my pockets...lol I've always kept up on it's maintenance. Prior to owning this one I had a 99 grand prix...so last month the transmission slipped. I was at stop sign, preceded to go, car jerked extremely hard..I pulls the car over, turn it off then turn back on and it wouldn't move in DRIVE. Something told me to put the car in another gear and it moved... Car only moves in reverse & 1st & 2nd gear, barely and slower. Aamco told me to either get it rebuilt or replaced.. I don't have $2200 to kick out.. I stumbled across the blog and it's amazing how many of you guys are experiencing this same thing.....This should definitely be apart of a major recall.. I love my Pontiac and I don't wanna give up on it.. what will the dealership do if I take it to them? The warranty expired on it back in October. and on top of this, I still have to make payments on the car as well..I seen someone mention another warranty the car might be under.. I think a 5yr powertrain.....PLEASE HELP!!

I wish I could post all over the internet . Do not buy a Grand pix or the tranny then put in the car does not have enough power for the motor. GM screwed everyone who bought one of these eventually you will have to have a new tranny. Why they cannot see this I don't know. Everyone I know who has owed one has had to replace the tranny . Wish I would have gotten off mine earlier. Other then that I love the car. But what a rip off GM

Well.....I'm back. In 2012 I reported here about my 2007 Pontiac Grand Prix GXP transmission going out at just 47,000 miles. I bought it new, took exceptional care of it.....always brought it to the dealer for maintenance....never even used the paddles since I bought it.

After a few days of going back and forth....GM agreed to put in a new transmission...if I paid $1000 deductible. I was reluctant.....but I had no choice.

Well here it is 5 years later.....but only 35,000 mileslater....and the exact same problem is occurring again.

Hi Everyone, I have an 08 GP GXP with 160000 kms on it. I bought it with 45000 kms and after putting about 30000 kms on it, The transmission started slipping. When its cold, I put into D or R and it doesn't even feel like it goes into gear at all. NO "drop" feeling or anything. Then after heating up it gets the proper feeling if I put it in P then D or R again. Also sometimes it will start to shift really hard then SES, service traction/stability system illuminates a few mins of driving. After a few days it stops shifting hard and all the illuminated lights turn off and repeats the cycle. Clearly there is a serious problem with these trannys!! I'm going to trade her in while the lights are not illuminated. Such a shame. I love the car otherwise. HUD is awesome too.

Let me think. You bought it with 30,000 miles on it. After about 20,000 miles more you noticed slipping? What service did you have done on the transmission at that time? Fluid and filter changed and refilled with proper Dexron VI fluid? You don't even mention the fluid color at the time of the symptoms as an anecdotal way of determining the degree of slipping and damage to the fluid.

Further, continuing to drive the vehicle with the slipping instead of fixing it doesn't help the transmission life.

And beyond that the hard shifting is the transmission computer adapting to not being able to control the shift time duration, so it goes into limp mode. This could be anything from a control valve needing service replacement to damaged clutch plates.

The car is GXP model with extra power. Was it driven in a more aggressive manner than normal? That can be to the detriment of a transmission.

"Clearly there is a serious problem with these trannys!!" begs the question of lack of timely service based on the report given here. I've had 3 of these transmissions in the H-body. Neighbors have had the GP models with the related transmission. Don't know of a single one with a failure. Neighbor currently has a GP with nearly 200,000 miles on it. Previous car was GP with superchaged engine and 150,000 mi when it was rear ended and totalled.

I'd check into a tranmission repair since they are very common and easy to work on. The idea of finding one in a junkyard with the GXP specs that's not been abused would be lower. I'd invest a $1500 into a good rebuild by knowledgeable shop.